Emeryville Marina neighbors have probably noticed the barge, tugboat and heavy equipment amid the vessels that appeared in June. The three-month long dredging project at the Emery Cove Yacht Harbor was contracted to Curtin Maritime and is being overseen by Emery Cove Harbor Master Diane Isley. About half of the Emery Cove will be dredged as part of this project.
Man-made Marina’s like Emeryville’s are prone to the slow build-up of sediment on the bay floor making them shallower. Heavy rains like we had last winter can expedite these deposits. Marinas must therefore regularly dredge to prevent damage to their boat’s hulls and facilitate safe navigation.
The cost of dredging the cove is an expected and ongoing maintenance cost and is paid for through the private Emery Cove slip fees. In addition, slip owners share half cost of dredging the access channel to both Marinas with The City of Emeryville. The private harbor maintains a budget to dredge approximately 50,000 cubic yards inside the Marina every eight years and half of an additional 50,000 cubic yards of the access channel every six years.
Emery Cove has 430 total slips and each boat must be temporarily shuffled to accommodate the large dredging equipment.
Curtin Maritime (CM), who are based out of Long Beach, were selected for the project via a competitive bidding process. Curtin Maritime also provide Ocean Towing and Project Cargo among other Maritime services.
The pride of Curtin Maritime’s fleet is their Sarah C 65′ Tugboat which is powered by two massive John Deere diesel engines. The whole operation remains anchored via two forty-foot posts on opposite ends. These posts are lowered through the water into the earth by a diesel winch system.
Soil analysis detects traces of PCBs for first time
This year, Isley noted that soil testing has yielded traces of PCB’s (Polychlorinated Biphenyls) in the deeper sediment for the first time in thirty-one years of monitoring. The impact of this means Emery Cove may only dredge to the -9.5 feet which tested clean as opposed to the preferred 10.5 ft.
PCBs were used widely in industrial products and chemicals until they were banned in 1979. Isley says that since the last dredging, permitting agencies have lowered the acceptable levels of PCBs in addition to more stringent testing methods.
The Marina itself remains fairly immaculate according to CM Project Manager Sam Bice and they’ve pulled up very little trash. Bice contrasted Emery Cove’s environmental quality with that of an unnamed Southern California Marina where he dredged 1000’s of aluminum cans, shopping carts, cables and hypodermic needles. Bice notes he’s pulled up propellers, munitions (detonated and live) and even historical artifacts that are required by law to be turned over to the state. As for buried treasure? Well, “finders keepers” as they say.
Offloads sent near Alcatraz
Dredgers work diligently to scoop the bottom layer of mud and fill the hoppers of their barge-mounted excavator. Once filled, the hoppers are towed to nearby scows anchored off the Emeryville shoreline.
Curtin Maritime then transports the collected sediment to a bay disposal site near Alcatraz since the sediment is deemed within tolerance. Isley says it’s much cheaper to move the sediment to Alcatraz than to an offshore dumpsite or upland disposal.
This maintenance dredging is expected to continue throughout early Fall. The dredging does not require any permits from the City according to City of Emeryville Assistant Planner Navarre Oaks, but does require permits from the US Army Corps of Engineers, SF Bay Regional Water Quality Control Board, and BCDC. The U.S. Department of Homeland Security must also be alerted of their operations.
The adjacent public Emeryville Marina, owned by the city, remains a separate endeavor with no dredging date set.
Next up, Dock Replacement
A permit was approved by the City Planning Department in June for the replacement of the existing Marina docks and gangways. Emery Cove is currently finalizing certifications and permits needed by the Army Corps of Engineers, the SF Bay Regional Water Quality Control Board, BCDC and one additional permit needed from the City Building Department.
The new dock system will be a state of the art model manufactured by the Canadian company Structurmarine. The system chosen is the Structure 80 which is an aluminum substructure on encapsulated floatation using untreated Ipe wood decking. These materials are A-1 fire rated, non-toxic, environmentally friendly and made from recyclable materials.
Emery Cove hopes to begin construction in November of this year after the completion of the dredging project. This will be a phased project and will take approximately 16 months to complete.
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